Headshots are not one size fits all. Sometimes a modeling shot can be used as an acting headshot, but most of the time they are not interchangeable. So what are the objectives for each and what makes them different?
What I can tell you, from my experiences, is how to survive as an actor. This is something any actor who’s stuck around long enough has struggled with, and it’s the toughest part of being a working actor. Here is what I’ve gleaned: